How to Reuse Coffee Grounds for their Hidden Potential


At the beginning of my coffee-making journey, I was throwing my used coffee grounds directly into the bin, without even questioning whether I can do something else with them.

Thankfully, one day my mom told me how to reuse the seemingly useless coffee grounds, pointing out that I could even apply them for skin improvement.

Once when I was at my parent’s house, my mom saw me emptying the coffee machine filter basket in the sink.

“Wait, wait, wait!” – she said.

It was too late – all the spent ground beans were already going down the drain.

She then explained that there were many uses for coffee grounds.

I thought she was being silly and laughed, as back then I couldn’t grasp the idea that there might be any benefits to coffee grounds other than to potentially make more coffee.

Which I knew wasn’t my mom’s intention, as she is the coffee snob from whom I inherited my love for this beverage.

She then explained that she stores them to make some sort of an anti-aging facial.

Other things that they could be reused for are treating dark circles under the eyes or as a scrub.

This is when I realized that there might be other potential uses for the already used ground beans so I started doing some research.

A while after we found out how to efficiently reuse coffee grounds as fertilizers and we started employing them for the garden.

It turns out they work great for skin exfoliation and they can help you reduce cellulite as well.

Used coffee grounds are a great addition to your recycling compost and can also be used as a deodorizer.

To this day I’ve tested quite a lot of ways to take advantage of spent grounds and I will point out the best ones in this article.

I’ve even experimented with reusing coffee grounds for a second cup of coffee, but more on that later…

Let’s begin.

How to best reutilize coffee grounds?

The ways to reuse your coffee ground beans that I will mention aren’t time-consuming.

I’m sure that you will end up loving them and some of them will become part of your life.

After a while, you may start asking yourself: “why haven’t I been doing that for longer…”.

So let’s stop wasting any more of your time and get to it.

To best reuse your coffee grounds you can:

1. Make your own deodorizer

Here is why using coffee grounds as deodorizer makes sense:

Spent coffee grounds can be reused as an odor absorber.

This is possible, as coffee grounds, even if you’ve already used them for your morning cup, have some caffeine left in them.

The caffeine contains nitrogen, which stimulates the process of adsorption.

In other words, your coffee grounds have the ability to trap smells.

Therefore coffee grounds can be successfully used as a deodorizer.

After I use my grounds, I dry them and place them in my used grounds jar.

When I cook fish, after I finish with the dirty job, I take a handful of the dried ground beans, place my hands above the sink and do the handwashing motion for 30-40 seconds.

After I’ve scrubbed my hands well, I rinse the grounds off with tap water.

And the fish smell is gone. Furthermore, I’ve simultaneously exfoliated my hands.

This is one of my favorite ways of how coffee grounds can be reused.

You can also utilize old used coffee to deodorize your car, by leaving an open container filled with the dried coffee beans under the driver’s seat.

The wider the surface of the container, the better results you’ll get.

You can reuse the spent coffee grounds the same way to absorb the bad smell in your fridge.

A friend of mine sprinkled his rug with his dried coffee grounds, instead of using baking soda, and left them overnight.

The next day he vacuumed them off.

He did that when he was suspicious about his cat peeing on it.

He was happy with the results he got. The bad smell coming from the carpet was gone.

But remember not to sprinkle light-colored carpets and rugs with coffee grounds as they might stain them.

2. Apply them to your home garden

Coffee grounds have diverse uses for gardening purposes.

I will only list those that I’ve personally tried and know they work because I did stumble upon a ton of misleading information online.

You can reuse your coffee grounds in your garden in the following ways:

1. In your compost

The nitrogen left in spent coffee grounds is highly beneficial to a compost bin.

It will actually give bacteria the energy boost they need to decompose the organic matter faster.

Being a nitrogen-rich ingredient in nature, spent grounds are considered as a part of the “green compost mix”.

Not only that – spent coffee has some other macronutrients such as potassium and phosphorus, which will enrich your compost and benefit your plants.

You should know that throwing too much spent coffee in the compost bin isn’t a good thing either.

Make sure your coffee grounds are up to only 20% of the volume of the compost.

Another benefit of adding spent coffee grounds to your compost is the fact that they will prevent the establishment of pathogenic fungi.

Old coffee residue can also be put to good use in a vermicomposting bin.

Earthworms simply love it.

Paper filters that you’ve used to prepare your coffee are a great addition to your composting pile as well.

Soak the filters in water and tear them into pieces to help them decompose faster (especially if they’re thick Chemex filters).

To be honest, I prefer adding only brown unbleached paper filters to my compost, but many people say that white paper filters won’t lower the compost’s quality.

I think it’s worth noting that adding spent coffee to a composting pile won’t result in acidic compost.

Used coffee grounds are mostly neutral in PH.

This doesn’t apply to fresh unused grounds.

The acids in the fresh beans are water-soluble.

This is why after they are used for a cup of coffee, their pH level gets higher, making them less acidic.

If you want to learn more about water chemistry and how it affects coffee extraction, check out this beginner’s guide on the best water for coffee.

2. As a mulch

First I need to point out the importance of the fact that mulching thick layers of spent coffee grounds isn’t good for your plants.

This is because grounds get compacted and block air movement.

This may also lead to soil moisture deprivation, as the layer won’t let water pass through.

Mind that if not composted, coffee grounds aren’t a nitrogen fertilizer.

Actually, it’s proven that they immobilize nitrogen in the soil, inhibiting the germination and the growth of some plants.

This is because through their decomposition process they attract microbes that use nitrogen, leaving the plants left out.

That’s why it’s overall better to recycle used coffee grounds by incorporating them in your compost.

Or just mix them with nitrogen fertilizer when being added directly to the soil.

It’s worth mentioning that while doing my research I also came across some studies, concluding that reusing non-composted coffee grounds could be beneficial for some plants, but the concentrations should be low. As an example you can see this study.

That being said, my mom’s been recycling spent coffee grounds, by freely tossing them on the lawn.

After sprinkling them randomly and emptying the bucket, she does her watering routine.

My mother is really happy with the fact that she’s been noticing more worms since she’s been doing that.

These invertebrates are strongly attracted by the coffee ground beans.

When she tosses the brown powder she says that she’s feeding her worms.

All gardeners know that earthworms are highly beneficial for the soil’s structure and richness.

She also places them around her flowers – roses, in particular, making sure they don’t have contact with the plant’s stem.

When doing that she mixes the grounds with the soil with her hands in order to prevent the soil from blocking incoming water and it works perfectly fine.

Note: A myth I often see spread around is that coffee grounds would repel slugs and other garden pests.

I have personally tried this multiple times and it has never worked for me.

3. Weeds removal

As I already mentioned, non-composted coffee grounds inhibit seed germination.

But this also means that they can reduce weed growth, so you can spread them around large trees, where you’re trying to reduce the weeds.

Trees won’t be affected by the spent coffee grounds’ inhibiting qualities, but weeds proliferation will be prevented.

3. Craft home-made cosmetics for your skin

There are several uses for spent coffee grounds when it comes to your skin:

1. An exfoliating face and body scrub

You can use your spent coffee grounds as a physical exfoliator.

By rubbing them onto your skin you will remove the dead skin cells.

By gently scrubbing your face or body twice a week, over time the skin’s collagen production will benefit from the procedure.

If you add a bit of olive oil, coconut oil, avocado oil, or honey to the used ground coffee beans, along with exfoliating, you will deeply moisturize and feed your skin with highly beneficial antioxidants and vitamins.

The ground coffee beans massage removes the dead skin layer, increases blood circulation, and makes it easier for the other scrub ingredients of choice to get deep into the skin and nurture it.

Feel free to experiment with the ingredients of your coffee scrub and see which ones work best for you.

I personally, scrub my face and body under the shower with plain spent coffee grounds twice a week.

After I finish showering, I’ve just exfoliated my skin and the steam has opened up my pores.

I use this opportunity to apply my moisturizing body lotion or coconut oil and massage my face with some hyaluronic acid serum.

It might be just me imagining it, but I can feel my skin soaking in all the beneficial components and it feels great.

Remember, that scrubbing too hard is bad for your skin, especially if it’s more sensitive.

When I scrub my face, I do it lightly as if it’s a tomato and I’m trying not to compromise the top layer of the fruit’s skin.

If you are gentle, you will avoid micro-tears.

It’s also important to note that coffee ground scrubs aren’t recommended for some people’s skin types.

So if you’re not sure whether this type of skin treatment will benefit your skin, consult a dermatologist before applying the scrub onto your face.

Anyway, I would also highly recommend anyone to use the coffee grounds and coconut oil lip-scrub.

I keep mine on my bathroom mirror cabinet.

It’s there so that I can see it and use it on a regular basis.

Doing so makes my lips feel much softer, smoother, and moisturized.

2. Anti-aging face masks

Spent coffee grounds are beneficial when used in a face mask, as they have some caffeine left in them – between 3,59 to 8.09 mg/g (according to this study).

It’s proven that caffeine has antioxidant qualities and it’s also proven it slows down photoaging.

This is why your spent coffee grounds are a great addition to your homemade anti-aging face mask, being beneficial for smoothing out wrinkles.

To a degree, caffeine also protects the skin from UV radiation.

This is my favorite anti-aging coffee mask recipe:

  • 2 tablespoons of spent coffee grounds
  • 1 tablespoon of yogurt

* Mix them well and apply on your face. Leave it for 10 to 20 minutes. After that rinse with water.

This mask is the one my mother told me about.

Yogurt contains lactic acid, which has a positive impact on skin complexion and rejuvenation.

Both coffee grounds and yogurt enhance each other’s anti-aging properties tremendously benefiting your skin and you end up with the perfect anti-aging DIY mask.

I highly recommend it for skin tightening and treating unwanted face wrinkles!

As I mentioned above, another benefit of caffeine applied to the skin is that it stimulates blood circulation.

A common cause of dark circles under the eyes is indeed the build-up of blood.

By applying coffee grounds under your eyes you may remove said build-ups and reduce inflammation, causing the shadowy appearance.

Used coffee grounds are a rather effective home remedy against dark eye circles.

3. Anti-cellulite solution

Caffeine prevents excessive accumulation of fat in cells.

Due to the fact that spent coffee grounds contain caffeine they can be used to reduce cellulite.

If you want to get rid of cellulite, grab your spent ground beans and massage them onto the affected skin.

The longer you massage – the better.

This way you will improve blood circulation while the caffeine stimulates the process of lipolysis.

While massaging your problem areas to get rid of cellulite, you are actually exfoliating your skin at the same time.

When you’re done with the process, you can shower off the coffee grounds.

If you are determined that cellulite has to go, apply your anti-cellulite lotion right after you’ve rinsed the grounds off of your body.

After this procedure, your blood circulation is increased in the problem area and at the same time, there is no dead skin layer that will prevent the active compounds to work their way deeper into the skin.

4. For your scalp and hair

Coffee grounds can also be reused by rubbing them onto your scalp while you’re in the shower.

Do that before you use your shampoo and conditioner.

By doing so on your scalp, not only will you exfoliate your skin, but you will also increase blood flow to your follicles.

This in effect stimulates hair growth.

If you use a lot of products such as hairsprays on a regular basis, the coffee grounds will help you remove the buildup.

They will also have a positive overall effect on your hair’s health and appearance.

So after you’ve rubbed the spent grounds for a short while on your scalp, just rinse them, and carry on with your regular hair-washing routine.

Using this scrubbing method could significantly reduce or completely remove dandruff as well.

I was hesitant to try this out as I thought it would be a struggle to remove the grounds of my hair.

But it’s not.

Just try it out, I’m pretty sure you’ll enjoy the results.

This massage method is a great example of the value spent coffee grounds have and how to reuse them in order to unfold their full potential.

How to dry and store for future use?

If you want to store the used ground beans for future use, you should dry them properly.

Drying is necessary to avoid the accumulation of fungi.

I’m pretty sure you don’t want moldy coffee grounds in your facial or body scrub.

Here is how to dry coffee grounds for further use:

You should place the used ground coffee beans in a shallow tray and spread them evenly.

Avoid layers that are too thick, as it will take longer for the grounds to dry out.

Place the trey somewhere (outside if weather conditions allow it) on a rather sunny spot and forget about it.

It shouldn’t take them more than a couple of days to dry out.

Most people place the grounds on paper, but I think they dry faster if I put them straight on the tray.

This is because the paper gets damp when you first place the grounds on it, and then it keeps the moisture for longer.

I like simple solutions, and changing the paper once a day seems a bit too much.

If I pass by the tray I simply stir them a bit and move on with what I’m doing.

You can also dry spent ground coffee in the oven.

To dry your coffee grounds in an oven:

  1. Place them on baking paper and spread them.
  2. Make sure the layer isn’t thicker than 2 inches (around 5 cm).
  3. Preheat the oven to 200 °F (100 °C) and place the tray into the oven.
  4. Stir the grounds every 10 minutes.
  5. Wait about 30 minutes and they will be dry.

After they cool-off they are ready to store.

But how to store your coffee grounds for future use without them losing their beneficial qualities?

Not complicated: Just place them in a jar and seal it. Make sure the inside of the jar is completely dry.

What’s worth noting is that coffee grounds’ beneficial compounds will be affected and will decrease while you dry them. The contact with oxygen and sunlight during drying decreases the amount of antioxidants your coffee beans contain.

If you want to find out more about how long coffee beans last (both ground and whole), visit this post.

Alternative uses

The aforementioned methods of reusing I mentioned are the ones that have become part of my life.

I’ve come across other ways of reusing coffee grounds, which I find a bit more difficult to incorporate on a day-to-day basis.

Some people say that they are great for washing older pots and pans, as by rubbing them in with a sponge, they remove the buildup nicely, without you having to use heavy chemicals. I’ve tried cleaning an old moka pot with spent coffee grounds, but it didn’t really work.

Related post: How to clean a Moka pot?

Other articles state that coffee grounds mixed with water can repair scratches on wooden furniture.

I’m pretty sure that it would work pretty well, but I would definitely avoid all the mess and just use sandpaper.

I tried to use coffee grounds to dye my paper to appear antique and it worked pretty well.

Here you can see exactly what I did:

As a first try it looks decent, I guess…

If you ignore my failure at trying the sophisticated handwriting, you will be able to see the coolness of the effect.

I felt like I’m 8 again.

Anyway, I might be doing that if I feel like making a special occasion greeting card for a loved one.

I’ve also tried reusing coffee grounds to make another cup of coffee and I wrote a whole article about that experience.

Visit the link to see my in-depth experiment and the included illustrations.

A short summary of the end results would be that it’s not a good idea, coffee doesn’t taste good, you don’t get the caffeine kick.

For me, it might only work if I make a second batch of cold brew coffee and add some milk to it.

The result is a pretty refreshing cold drink with a slight coffee flavor.

Conclusion

To sum everything up – definitely, don’t throw away your spent coffee beans after you’ve used them for your cup of coffee and take advantage of the many uses they could serve for.

If you don’t have a compost bin, save some money by preparing a DIY scrub, or facial mask.

Use them as a deodorizer, or as a scalp exfoliator.

Let the spent grounds rejuvenate your skin.

Don’t let all the antioxidant and other beneficial components go to waste and do yourself a favor, by employing the multiple benefits of coffee grounds and the ways they can be reused.

It’s worth it.

Tell me if you have any other suggestions for their reuse by dropping a comment below.

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